Hello all,

First off, if this is not the correct place to post this questions please feel free to move it or advise me of what I need to do. I was a member years ago but I was never really all that active and I've long since forgotten how things work around here. Anyway here's my problem.

84 Camaro Sport Coupe 2.8L with the old 2 barrel carburetor. For years now my gas gauge has been showing anywhere from 4 to 6-ish? gallons low. To the point that the needle will actually drop down below empty and well into the black unmarked section of the gauge face. My initial thought was problem with the fuel float/sending unit. SO...I've just completed dropping the tank, replaced the fuel sending unit (desperately needed to be replaced anyway), bolted everything back together, put a good 5 gallons of gas in it, reconnected the battery, turned the key to "ON" position and......my fuel gauge still shows 0 or maybe just barely above 0.

On the off chance that maybe it would sort itself out once I filled the tank, I went to the gas station this morning and filled the tank. Sure enough, still shows between 3-4 gallons low. (just as I figured it would). My next thought is that is has to be either the gauge itself or something wrong with the wiring but I'm not sure how to troubleshoot which might be the real root of the problem. I'd greatly appreciate some advice as to how to attack this problem.

I've also noticed something that seems particularly strange to me. The needle on my fuel gauge moves in conjunction with my speed. For example, if I romp on the gas and accelerate, the needle will rise just a bit. When I hit the brake, the needle falls. I can't for the life of me think of why the gas gauge would be responding in that manner. Any thoughts??? (And before someone states the obvious...no I'm not mistakenly looking at the speedometer lol)

Also, and this may be a question for another thread....if it turns out to be the gauge that is faulty. Does anyone know where I may find an OE replacement? It's the Metric/standard one with the white and orange face place. The left side is liters and the right is gallons, 16 gallon tank. Any help locating one would be greatly appreciated.

UPDATE: disconnected the two pin connector coming off the sending unit, disconnected with key ON the gauge shot up way past full and I'm getting a reading of 94.7 ohms. If I remember correctly our cars should be at 90 ohms full?? Thoughts?

 

The gauge works on a 0-90 ohm range. Buy a pack of resistors. If you ground the gauge wire directly it should go to E. If you put a resistor of 90/2 or 45 ohms then it should show 1/2 tank. You can do this with 90/3 (1/3 tank) and 90*2/3 (2/3 tank) ohm resistors to verify a few spots. Then try it with a 90 ohm resistor and it should read F. You can buy a Potentiometer that will go 0-90 ohm also and just dial it in with a meter and test vs a bunch of resistors. You can add two resistors to get the right value also (a 10 ohm connected to a 35 ohm would be 45 ohm)

Do the above with the sender disconnected.

Ohm the wire between the connector at the cluster and the connector at the tank, it should be pretty close to 0 ohms.

The bulk head connector that is behind the rear seat back is a possible place where you could end up with resistance or short to ground etc that could throw off the value so test there also.

At the gauge with the sender connected but the cluster disconnected. With a full tank you should have about 90 ohms between ground and the pin, with it 1/2 45 ohms, with it empty 0 ohms (or straight ground).

If the sender is outputting the right ohm for the position, and there is no major resistance in the wiring or connectors then its probably the gauge.


For example if you have a 13 gallon tank and its reading 3 gallons low that is 76.9% the value it should be. So that should mean if its the sender then with a full tank the cluster pig tail would read around 70ohms (instead of the correct 90 ohm) if the issue is in your wiring or sender. That may be an easier test to start with if you don't mind taking the cluster out. The same error would be 34 ohm instead of 45 at 1/2 tank. Since 0 is empty you can't go below this value so to me that is a hint its the gauge.

Its late on a Thur at work so hopefully that math was right and this made sense.

 

Aviator857,

Thanks for the reply. I'll have to pick up some resisters and tear into the gauge cluster this weekend. Hopefully I'll be able to make some progress at least. If it does turn out to be the gauge, any idea's on where to find a replacement?

 

Used Hawks or eBay. Or local bone yards

 

Used Hawks or eBay. Or local bone yards

 

I thought of Hawks too, unfortunately they don't have anything even close to resembling my gauge. Didn't seem to have much luck on Ebay either. I've decided I'm just going to order an aftermarket 2 inch gauge and mount it on that trim piece between the edge of the windshield and the dash pad.

I still plan on going through the car this weekend just so I know exactly what is happening with the gauge, and to verify that all my grounds are good but I figure even if I do find a replacement gauge it's going to cost a pretty penny and at this point I'd rather spend the money on my engine swap.

Thanks for all of your help!

 

There are cluster repair shops that you can send it to. About 80% of the time it's electrolyte leaking out of capacitors, so if you open it up and see anything that looks like rosen around a capacitor and you have the skills desolder the cap and replace. There are YouTube how toos.

Post a pic of your gauge, also there are several junkyard that specializes in fbody. Put up a request in the classified section for looking to buy.

More than likely you could use the guts of a fuel guage from a newer thirdgen cluster and keep your existing face. I tend to just tear in and assume I can figure it out, and most of the time I do.

 

One other thought if someone ever had the needle off the gauge they may have clocked it wrong, you could pull it off and try to re clock it.

Look for the full cluster not just the fuel guage https://www.ebay.com/itm/1984-Chevy-...8AAOSwq6Nc9xIj

Most of the clusters are interchangable up till they switched over to electronic speedometers vs cable driven. The Tach and the top MPH being the only real difference between the different engine options. Though you may have to get the right pigtail and re pin it etc.

 

Well what you found on Ebay is a lot closer than anything I found. All I could come up with was the little 2 inch once that you see on IROCs and Z28s. Still not quite correct but you're right, I could just swap the faces. Admittedly the price is a lot better than I was expecting as well.

I planned on putting out some feelers in the classified section once I know for sure the gauge is faulty. At this point I'm about 85% sure it is the gauge but, I'd rather be 100% before I start bugging people and begging for precious parts.

I have a feeling you're right on the money about the needle being clocked wrong. Or at least it's playing a part in it. I know I haven't touched it as long as I've had the car but the guy that had it before me may have.

Here's the gauge I'm looking for btw. For whatever reason it seems to be somewhat rare.

 

So that is a combo gauge (its fuel and what?), Or wait that is liter and gal, does your speed o have the same set up with mph and kph? If so you have a car that wasn't built for the US market originally. It was probably originally sold in Canada. I admittedly don't know the camaro as well as the firebird. I think they changed the cluster in 85 to the small gauges. So you are looking for 82-84 base model from a Canadian or international build car.

The cluster I sent you should work unless you actually need/want to keep the metric readings also. Just swap the fuel gauge into your cluster so your mileage is right (if you care about that)+

https://www.ebay.com/itm/1982-CAMARO...gAAOSwfcFc5ugf

https://www.ebay.com/itm/SPEEDOMETER....c100009.m1982


Actually looking I think the 82 had the kph/mph liter/gal guages in all countries so you may just have a 82 cluster in your 84? So the US/International market may be wrong.

 

Yes, it is a combo gauge, litres and gallons. The speedometer is the same way with KPH/MPH. My understanding has been that this was the norm because it was during the whole metric conversion attempt when the US government was trying to get people used to the idea of converting to the metric system that ultimately failed. Could be wrong though.

I actually ran the VIN years ago and I'm pretty sure the car was built in the US but that doesn't necessarily mean it wasn't built to go to Canada. If I can I'd like to keep the original gauges on there, I think it just adds a little character to the car and a little bit of a "wow" factor since for whatever reason it seems to be somewhat hard to find. That's why i was thinking about just grabbing a cheap aftermarket 2 inch and mounting it on the dash or something, so I could at least keep it original even if the original gauge isn't functional.

I'll have to do some digging and soul searching to decide exactly how I want to go about things. Maybe just picking up a gauge cluster like you mentioned and swapping the face is the way to go. Time will tell.

 

That last cluster on eBay I linked had the metric and sae. I would not call it rare there were alot of 82 to 8 base models made, but not alot of people listing parts off those. Nothing prevents you from making it work for now and keep the factory guage for later.

 

Fuel will slosh around in an unbaffled fuel tank, dependent on the car's motion. With the way the sending unit in a 3rd gen is designed, if you accelerate, fuel moves to the back of the tank, lifting the float on the sending unit, causing the fuel gauge to show an increase. Conversely, when braking, fuel goes to the front of the tank, lowering the float and causing a comparative change in the gauge reading.

 

Aviator857,

Just wanted to say thank you for the help! I ordered one of the clusters you found and popped in the fuel gauge this weekend and everything is reading as it should. As easy as it was I can't believe I've been driving the car with a busted gauge for all these years. Thanks again for the assist!

ironwill,

For some reason I didn't see your post until just now, but thanks for the response, that's actually kind of what I was thinking but I couldn't quite put it into words or justify in my mind why it would be doing that. Seems you're absolutely right, so I'll not worry about it. All in all I'm just glad I can finally get an accurate reading (or at least I can when the car is level or parked)

Thanks again to both of you!